Two phone retailers, Sean Ting and Szu Chen, posted an advertisement on Craigslist last month stating they wanted to buy iPhones. A man who identified himself as "Matt" contacted the men and said he knew people who would sell them the phones, the document states.

They arranged a time to meet to buy the phones.

During the transaction, one of the supposed sellers pulled a pistol and placed it on Ting's head and demanded money. Ting told police that he cooperated and raised his hands above his head.

Chen told police that at the same time, another robber demanded money at knifepoint, the document states.

When two of the attackers turned their attention to Chen, Ting produced his own pistol and told them to stop. Both Chen and Ting are concealed handgun permit holders. The robbers then ran.

Ting and Chen chased after their attackers. One of the attackers fired at the men, who then fired back, the document states.

The men were able to capture one of their robbers, later identified as Sidney Diosdado, who was arrested by the Harris County Sheriff's Office at the scene. Investigators determined that a juvenile, who is not identified, set up the robbery, the document states.

The third attacker was later identified as Steven Diosdado.

Steven Diosdado is in custody and faces $30,000 bail. Sidney Diosdado posted bail and was released.